Essential Biochemistry - Neurotransmitters (Section 3 - No. 1)
Excitatory neurotransmitters:
Cause hyperpolarization in the postsynaptic membrane.
Make it more difficult to generate a nerve impulse.
Cause depolarization in the postsynaptic membrane.
Prevent the generation of action potential.
Explanation
Excitatory neurotransmitters depolarize the postsynaptic membrane, making it easier to generate a nerve impulse.